Development of Alternative Energy Saving MBR Using Reciprocating Vibration in Place of Membrane Air Scouring

Membrane Bioreactors (MBRs) are becoming popular for advanced wastewater treatment and water reuse. However, mitigating technologies for membrane fouling are energy intensive. Leading these technologies is air scouring, which is used to ‘shake’ the hollow fibers, reducing the fouling rate and maintaining filtration flux. The goal of this research is to develop an alternative, energy saving MBR system to reduce energy consumption. Such a system is potentially revolutionary and will directly compete with air scouring technologies currently used in the membrane water reuse market. The innovative MBR system, called Reciprocating MBR (RMBR), inhibits severe membrane fouling without the use of air scouring blowers. The mechanism is a mechanical, reciprocating membrane frame that uses inertia to inhibit fouling. Direct, strong agitation of the fiber is beneficial for the removal of solids built up on the membrane surface. This mechanism is unlike any other on the MBR market. The RMBR pilot consumes less energy than the coarse air scouring used in conventional MBR systems. Specific energy consumption for membrane vibration for the pilot RMBR system was 0.15 kWh/m3 permeate produced at a flux of 20 LMH, which is 25∼50% less than conventional air scouring MBR system (0.2 to 0.3 kWh/m3). The energy consumption can be further reduced with high flux operation. Reciprocating vibration of the hollow fiber membranes can overcome the hydrodynamic limitations of the air scouring or cross-flow membrane systems with less energy consumption and/or higher energy efficiency.